With shield bash it is even more important: strength counts twice.
Strength together with weapon damage is responsible for the damage value of a glad.
SHIELD_ATK=random(DMGMAXSHIELD_T-DMGMINSHIELD_T)+DMGMINSHIELD_T
with:

DMGMINSHIELD_T=DMGMINSHIELD+STR x 2

DMGMAXSHIELD_T=DMGMAXSHIELD+STRx 2

shieldbashers use this damage property where strengh counts double to deliver high damage

Crit

Shieldbash has a normal crit probability 1/10 shield bash crits as often as 10/10